1. Field of the Invention
The present invention relates to a growing method of low-dimensional quantum structures, and more specifically to a method for growing high quality GaAs quantum dots by using a chemical beam epitaxy (CBE).
2. Description of the Prior Art
Ever since the advantages of zero-and one-dimensional semiconductor heterostructures were predicted the formation of high-quality quantum wires (QWRs) and quantum dots (QDs) has been of much interest. The formation of quantum dots has attracted particular attention due to three-dimensional quantum confinement effect, that can potentially lead to the understanding of new physics and optoelectronic device applications.
For this purpose, various approaches have been proposed and, of these, the preferred one was nanolithography. In this method, a pattern is first defined by high-resolution lithography and is subsequently transferred to a semiconductor quantum well substrate by dry chemical etching and/or impurity disordering using an ion beam implantation. These methods, however, have suffered some drawbacks, such as limited resolution and defects created by etching.
In order to decrease the damage level and the contamination, Stranski Krastanow (S-K) growing method has been disclosed. The S-K growth has advantages over the nanolithography method, because it has low damage level and contamination, and the density of nanostructure is not restricted by the resolution of the lithography processes. Until now, quantum dot structures have been mostly grown by using Stranski Krastanow mechanism.
However, this S-K growth has several disadvantages, such as limitation of material systems and generation of defects. In addition, this method is not used in lattice-matched material systems.